In addition to only being able to pay in a certain amount of money in each tax year, another restriction is that you can only pay into one of each kind of Isa in the same tax year.
This means you can only make new deposits into one cash Isa (if you have a Help to Buy Isa this counts as being your cash Isa option), one stocks and shares Isa, one innovative finance Isa and one lifetime Isa.
The only condition is that you top up your Isa in the same tax year the withdrawal was made.
If you put it back in the next year, it will count towards your new annual allowance.
After that, you'd still have £15,000 left of the current year's Isa allowance to use.
This flexibility is not compulsory and isn't available on all Isas - only 19% of cash Isas and Junior cash Isas offered flexible withdrawals when Which?
If you've already paid into, say, a cash Isa and see a better rate on the market, you may still be able to take advantage of it by transferring your Isa savings to the new provider.
Paying the money back, the £10,000 from the previous year is 'topped up' first, then the £5,000 from the current tax year.There is a maximum government bonus of £3,000 on £12,000 of savings.You can open your Help to Buy Isa with a one-off deposit of £1,000 to kick things off, and then add £200 per month thereafter.For the 2019-20 tax year, everyone has an Isa allowance of £20,000 - this is the maximum amount you're allowed to pay into Isas between 6 April 2019 and 5 April 2020. If you don't use your annual Isa allowance before the end of each tax year, you'll lose it - and it will start anew on 6 April.
If you want to skip this and go straight to some of the best cash Isa rates on the market, head to Which? Savers can deposit the full £20,000 into a cash, stocks and shares or innovative finance Isa, or any mix of the three types.
If you're saving up to buy property, there is also the Help to Buy Isa and, for those aged 18-40, the lifetime Isa.